Thermostatic apparatus.



B. V. EDWARDS.

THERMOSTATIC APPARATUS;

APPLICATION FILED'MAR- 28, 19M.

Patented J an; 2, 1917.

Inventor: O Attys- UNITED STATES PATENT OFFICE.

BRUCE V. EDWARDS, OF NEWARK, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGNMENTS,TO THE JEJ'J'RCI-IFLLLJOIINSTON CORPORATION, A CORPORATION OF NEW YORK.

THERMOSTATIC APPARATUS.

specification of Letters Patent.

Patented J an. 2, 191 '7.

To all whom it may concern:

Be it known that I, BRUCE V. EDWARDS, a citizen of the United States,residing at Newark, in the county of Essex and State of New Jersey, haveinvented certain new and useful Improvements in Thermostatic Apparatus,of which the following is a specification, reference being had thereinto'the accompanying drawing.

This invention relates to thermostatic apparatus operating to control anelectric circuit for sounding an alarm, operating sprinkler systems, orperforming other functions, and the invention has special reference tothat type of apparatus in which the volumetric changes of a fluid body,such as are due to temperature changes, will operate to control thecircuit.

The object of the invention is to produce a device of this characterdesigned more particularly for use in rooms, halls, warehouses and likesituations, for indicating the presence ofa fire or conflagration, whichdevice will be compact in form, and simple in construction; and whichdevice while un-' der gradual temperature changes, such as climaticchanges and those ordinarily occurring in such locations, will notoperateto perform its functions, yet will be very sensitive to actionunder sudden'temperature changes,-and in such conditions will operateumn will be raised by the expansive action of the fluid in the chamber,and suitable means operated by the rise of the liquid column, to controlan electric circuit. p

The inventlon conslsts also in the details "of construction andcombination of the parts hereinafterdescribed and claimed.

. o In the accompanying drawings: Figure l close a normally opencircuit.

the circuit. Fig. 2 is a sectional elevation of a modified form of theapparatus.

Referring to the drawings: 1 represents a fluid expansion chamberinclosed by a wall, consisting of the hemispherical metal caslng 2, andthe circular plate 3 fitting wlthin the casing near its edge, and sealedfluid-tight-therein. The chamber is adapted t0 contain air, which is theexpansive fluid employed in the present instance, and the thickness ofthe casing 2 is such that while it will possess the necessary'rigidity,it will permit the contained air body to be promptly influenced by theexternal temperature changes.

Extending into and surrounded by the chamber, is an upright tube 4 openat both ends, the upper end of whichis fixedly secured. in an opening'inthe center of the plate 3, while its lower end terminates a shortdistance above the bottom of the casing 2, which latter is depressed ordeepened at its center so asxto form a well 2*. Within the casing isplaced a'quantityof liquid 5,

preferably glycerin or oil, in volume sulficient to fill the well 2 andto spread out in the bottom of the. casing, so as to present its uppersurface to the expansive action of the air in said chamber. As a resultof this constructlon and arrangement of the parts,

an increase of temperature of the air outside the casing, will heat theair body in chamber 1, andthe'pressure on the surface of the liquid willforce the same up into the,

tube,in the form of a column 5. I propose to utilize the rise of thecolumn, 5, to control an electric circuit, in the present case tofected" in the form of apparatus shown, by means-of a contact body inthe form of a float 7 of conductive material, which is sup-.

ported on the upper end of the column 5. This float when raised by thecolumn, is adapted to contact with the inner ends of two electriccircuit terminals 8 and 9 con- This is efnected' with but insulated fromthe plate 3,

and having their'inner extremities in position to be engaged by thefloat as described,

'by which action the circuit will be closed.

9 of the circuit. The above described operations are adapted to takeplace only in the event of a sudden rise in temperature outside of thecasing 2, such as would occur from a fire or confiagration, and in orderto insure this action and prevent the column from being raised bygradual temperature changes such as ordinarily occur from climaticchanges and from the ordinary heating of the room, I provide a ventopening 10 in the wall of the chamber 1, in the present instance thisopening being formed in the plate 3. This opening is of such size thatwhile it will permit the air to escape when the expansion of the airbody is slow and gradual, andin this way will prevent a sufiicientincrease in volume to raise the liquid column, yet it will not preventsulficient air to escape when the expansion in the, chamber 1 is rapidor sudden,-to check such increase in volume of the air as to elevate thecolumn. Therefore it. is only under conditions of a sudden increase oftemperature on the outside of the casing, that the expansion of the bodyof air in chamber 1 will act to raise the liquid column.

By the provision of the Well 2 in the bottom of the casing 2 acontracted space is formed at the lower end of the tube into which theliquid must enter before it can rise in the tube. Hence when the levelin the chamber is reduced by the rise of the liquid in the tube, therewill be no liability of an interruption being formed between the liquidin the column and that remaining in the chamber. 7

In the attachment of the apparatus to the ceiling for instance, Ipropose to employ a block 11 which is adapted to be fastened in place bysuitable means. This block contains a central opening 11 through whichthe conductors from the terminals pass to theline. Secured to the lowerface of the .block is a plate 12 provided at opposite sides withoppositely extending keyhole slots 13 adapted to receive headed pins 14projecting upwardly from the plate 3. In fastening the casing inposition, the latter is applied to the under side of the block and thepins let entered in the ends of the keyhole-slots, whereupon the casingis given a slight circumferential movement so as to interlock the headsofthe pins with the edges of the slots.

In the modified form of the apparatus shown in Fig. 2, the constructionis the same as that just described except in respect to the float 7,which in this case is in the form of a cup '2' containing a conductivebody 7 preferably of mercury. The ends of the terminals are extendeddownwardly vertically as at 8 and 9 in such position that while undernormal conditions the level of the mercury will be below and out ofcontact with the terminals, yet when the cup is raised by the rise ofthe liquid column,- the mercury body will be carried into engagementwith the terminals and will form an electric connection between them andthus.

close the circuit.

-The conductors of the electric circuit are shown in the present case asconnected with a device A, which may be an alarm bell adapted on theclosure of the circuit in the manner set forth to be sounded to give analarm. It will be understood however, that the apparatus is not limitedin its application to a signaling device of this type, as the electricconductors may be connected up to operate other devices, such assprinkler systems, and to perform other functions, the inventionresiding in the construction of the circuit controller itself, withoutregard to the detailed construction of the apparatus operated by thecircuit.

By forming the vent opening 10 in the plate 3, said opening is housed bythe plate 12 and block 11 from direct communication with the spaceexterior of the casing 2, although the fit of the casing 2 against theblock is not sufiiciently tight to prevent the escape of the air fromthe expansion chamber to the outside. As a result, the vent opening,which is of a very restricted character to perform its functions, isprotected against the entrance of dust or dirt from the space in theroom, and the liability of the opening becoming clogged up by foreignmatters, is reduced to a m1nimum. In the foregoing description and in thaccompanying drawings I have shown my invention embodied in theparticular form and detailed construction which I prefer to adopt, butitwill be manifest to the skilled mechanic that these details may bevariously changed and modified without departing from the limits of theinvention; and it will be understood that the invention is not limitedto any particular form or construction of the parts except in so far assuch limitations are specified in the claims.

Having thus described my invention, what I claim is:

1. In a thermostatic controller, the combination of a hollow opencasing, a plate fitting over the end of the same and consti tuting inconnection therewith a fluid expansion chamber, a liquid column in saidchamber adapted to be raised by the expansive action of the fluidtherein and acting when raised to control an electric circuit, a supporting block provided with slots, and pins on the plate adapted toenter the slots and effect a detachable connection of the casing withthe block.

2. In a thermostatic controller, the combination of a hollow opencasing, a plate fittedin the open end of the casing and constitutlngin,connect1on therewith a fluid expanslon chamber, a liquid column insaid 130 chamber adapted to be raised by the exbe protected by the blockfrom the direct enpansive action of the fluid, an electric cirtrance ofdust or dirt therein. 19 cuitadapted to be controlled by the rise of Intestimony whereof I have aflixed my the rliquld column, and a.supporting block signature in presence of two witnesses.

5 to the face of which the plate and connected BRUCE V. EDWARDS.

casing are detachably connected, the said Witnesses: 4 plate beingprovided with a restricted vent JNO. SAUERWEIN,

opening; whereby the said vent opening will HERBERT Dixon.

